I would like to calculate the double integral

int(int((f(rcos(teta),rsin(teta)),r=1/sin2(teta)-cos(teta)..2sin(teta)),teta=pi/8..pi/2)

Where f:=(rcos(teta),rsin(teta))->1/(2sqrt(r^2cos^2(teta)+r^2sin^2(teta)))r

But i only manage to calculate the inner integral on maple. The assignment says that there should be an answer just that it will be very long but an answer where the second integral is not calculated is not an answer?